CVE-2026-21872
Medium
Description
NiceGUI is a Python-based UI framework. From versions 2.22.0 to 3.4.1, an unsafe implementation in the click event listener used by ui.sub_pages, combined with attacker-controlled link rendering on the page, causes XSS when the user actively clicks on the link. This issue has been patched in version 3.5.0.
SeverityMedium
CVSS6.1
Exploit probability—
ProductZauberzeug Nicegui
PublishedJan 8, 2026
First seenJan 8, 2026
Weakness typeCWE-79Cross-site scripting (XSS)
How to fix
Update
- zauberzeug nicegui3.5.0 or later
- nicegui3.5.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| zauberzeug nicegui | 2.22.0 ≤ v < 3.5.0 | 3.5.0 |
| niceguiPyPI | 2.22.0 ≤ v < 3.5.0 | 3.5.0 |
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